over the past year i have seen many job offers for turkey on the international job board. however, recently there are almost no job postings for turkey. does anyone have any ideas as to why that would be?

Just because the more popular sites are not advertising jobs for Turkey does not mean that there is a glut of teachers over here ,the opposite is true . Not every seeker of new staff uses the net many advertise locally or through their local British Council or just through word of mouth,if you are a known quanity and people are prepared to recommend you doors will open as if by magic .